Synthetic polymeric materials are being used in extensive areas because of their excellent properties. If provided with antistatic capability in addition to the mechanical properties peculiar to them, these materials can find more areas of application. That is, they can be used for parts of electronic and electric machines such as copiers and television sets desired to be free from electrostatic trouble, parts of various dustproof apparatuses, their housings, etc.
Synthetic polymeric materials have been generally provided with the antistatic property (1) by kneading a water absorbable compound such as polyalkylene oxide, antistatic agent, etc. with the polymer concerned, or (2) by coating the polymer on the surface with a surfactant, etc. Either method fails to provide a satisfactory antistatic property and cannot avoid such problems that rinsing or surface wiping decreases the antistatic capability, or that the ingredient contained bleeds out onto the surface, to degrade the quality of the material, and that the antistatic property is degraded by secular change.
These problems have not been solved so far. In this situation, the inventors studied intensively for the purpose of developing intrinsically antistatic resins with permanent antistatic capability, and as a result found that said purpose can be efficiently achieved by mixing certain polyether ester amide with at least one thermoplastic resin selected from styrene based resins, polyphenylene ether resins and polycarbonate resins in specific proportions. Thus, the present invention has been completed.
Compositions similar to those of the present invention include those disclosed in EP167824 (A) which are prepared by adding a polyamide elastomer to a styrene based resin and/or a polyphenylene ether to enhance the wear resistance of the styrene based resin.
EP167824 is intended to enhance the wear resistance of styrene based resins, and does not refer to any description nor suggestion concerning their permanent antistatic property.